EVA Films Loaded with Layered Double Hydroxide (LDH) Modified with Methacrylic Anion: Effect of the Nanohybrid Filler on the Photodegradation Phenomena.

Giuliana Gorrasi,Alessandro Di Mauro,Gianluca Viscusi,Andrea A Scamporrino,Gabriele Clarizia,Paola Bernardo,Maria Cantarella,Giusy Curcuruto,Sabrina Carroccio

doi:10.3390/polym13152525

Abstract

The photo-oxidative studies of ethylene vinyl acetate copolymer (EVA) matrix, filled with Layered Double Hydroxide (LDH) modified with methacrylic anion (MA), were herein reported, together with gas permeation tests. The formulation of nano-hybrid LDHs was characterized using X-ray diffractometry (XRD) and thermogravimetric analysis (TGA), demonstrating the partial intercalation of the 30% of MA anion between the LDH’s galleries. The as-modified filler was introduced into an EVA matrix by mechanical milling, producing free-standing films subjected to accelerated aging. Fourier transform infrared spectroscopy (FT-IR) results suggested that the nanohybrid presence determined a stabilizing effect up to 45 days of UV irradiation, especially if compared to the EVA/LDH references for all formulated EVA hybrid nanocomposites. Conversely, the presence of nanohybrid in the matrix did not significantly change the thermal stability of EVA samples. The dispersion of modified MA-LDH in the EVA matrix produces defect-free samples in the whole range of investigated loadings. The samples show a slight decrease in gas permeability, coupled with a substantial stabilization of the original CO2/O2 selectivity, which also proves the integrity of the films after 30 days of UV irradiation.

Highlights

The primary worldwide source of energy mainly derives from fossil fuels, whose reservations are constantly decreasing
The as-prepared Layered Double Hydroxide (LDH)-methacrylic anion (MA) nanohybrid was characterized by X-ray diffractometry (XRD) and thermogravimetric analysis (TGA) measurements
In the case of LDH-MA, the second degradation step resulted as anticipated for the presence of the intercalated MA

Summary

Introduction

The primary worldwide source of energy mainly derives from fossil fuels, whose reservations are constantly decreasing. The understanding of aging processes involved during outdoor exposure for each component of the photovoltaic module becomes of outstanding importance [2,3,4,5] One of these elements comprises the ethylene vinyl acetate copolymer (EVA) as an encapsulation agent. By adding a specific filler to a specific matrix, great benefits in terms of mechanical properties can be obtained, and vice versa, the same filler can determine a depletion of UV durability This phenomenon can be tuned, depending on the chemical composition of the nanofiller, its UV and thermal stability, its morphology and the possible interactions and/or reactions that may occur between the matrix and nanofiller [16].

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Results

Conclusion